This study was performed in northern Iran, where the consumption of opium is very common. The researchers say that this is the first study to compare death risk among opium users versus non-users.
Approximately 20 million individuals globally use opium derivatives or opium itself. Previous studies have suggested that opium might raise the risk of developing bladder and throat cancers, coronary heart disease, as well as some other conditions and illnesses. However, not much has been known about opium's effect on overall mortality, especially long-term low-dose usage.
An international team of researchers set out to find out whether opium usage might be linked to subsequently higher death risk.
They gathered data on 50,045 adult males and females over a period of five years. They were all from the Golestan Province, northern Iran, and were aged from 40 to 75 years.
17% (8,487) of them said they used opium, for an average of 12.7 years. During the study period 2,145 deaths were reported.
The authors found that opium usage was associated with an 86% greater risk of death from several causes, including asthma, COPD (chronic obstructive pulmonary disease), TB (tuberculosis), cancer and circulatory diseases. They reached this figure after taking into account several factors that also drive mortality numbers, including poverty and tobacco smoking.
In a communiqué, the BMJ wrote:
"Even after excluding those who self-prescribed opium after the onset of a chronic illness, the associations remained strong and a dose-response relationship was seen."
All different types of opium were associated with higher mortality, including ingestion and smoking.
The authors say that about 15% of all deaths in this sample population are linked to opium usage, assuming that this represents a causal association. Further studies are required to look into what impact long-term opioid analgesics might have on mortality among patients being treated for chronic pain.
Opium (lachryma papaveris) is the dried latex obtained from the opium poppy (Papaver somniferum)